Clean utilization method for municipal sludge

Abstract

The invention provides a clean utilization method for municipal sludge. According to the method, the municipal sludge is subjected to high-temperature anaerobic fermentation, then, a thiobacillus thiooxidans enriched bacterial solution is added for culture, and finally, the municipal sludge is dehydrated. By the clean utilization method for the municipal sludge, provided by the invention, biogas can be produced and prepared at an anaerobic digestion stage; after heavy metals are removed through thiobacillus thiooxidans treatment, the sludge can be fully decomposed; meanwhile, for municipal industrial sludge, in the case that the content of the heavy metals is in the range of exceeding the heavy-metal limit value, specified by the national sgricultural standard, by five times, the heavy metal removal effect is good, the removal ratio can reach 90-95%, the treated industrial sludge can fully meet the agricultural requirements of sludge, is made into all types of organic fertilizers, is applied to landscaping, agricultural use and the like and is used for increasing the content of organic matters in soil and improving the structure of the soil; whereas, for municipal domestic sludge, the heavy metal removal effect is more obvious.

Description

technical field [0001] The invention relates to a method for cleaning and utilizing urban sludge. Background technique [0002] During the 12th Five-Year Plan period, my country's urban sewage treatment plants will produce 35 million to 60 million tons of sludge with a moisture content of 80% per day. Municipal sludge is rich in nitrogen, phosphorus, potassium and organic matter, and using it as organic fertilizer is the most economically feasible and promising disposal method, but the high concentration of heavy metals in it limits this disposal method. [0003] In the existing sludge treatment and disposal, the method is relatively simple. Sludge with low heavy metal content is often treated by high-temperature composting and applied to landscaping and agriculture. For urban sludge with high heavy metal content, methods such as incineration and brick making are generally used. The utilization rate of sludge resources is low, and it is easy to cause secondary pollution to...

AI Technical Summary

Problems solved by technology

For urban sludge with high heavy metal content, methods such as incineration and brick making are generally used. The utilization rate of sludge resources is low, and it is easy to cause secondary pollution to the environment.

In the harmless treatment of heavy metals in sludge, there is currently no suitable process for large-scale treatment